Railroad-crossing signal



Aug. 6, 1929. a gM 1,723,895

RzflLROAD CROSS ING S IGNAL Filed Jan. 12, 1929 2 Sheets-Sheet 1 Aug. 6, 1929. B 5M|TH 1,723,895

RAILROAD CROS SING SIGNAL Filed Jan. 12, 1929 2 Sheets-Sheet 2 Lil w Frankfl Jmzik,

ATTORNEY Patented Aug. 6, 1929.

PATENT OFFICE.

FRANK B. SMITH, OF PITTSBURGH, PENNSYLVANIA.

RAILRDAD-GROSSING SIGNAL.

Application filed January 12, 1829. Serial No. 332,031.

This invention relates to a railroad crossing signal, the general object of the invention be ing to provide treadle members so located that they will be depressed by a train pass ing over the track and approaching the crossing, with signal means arranged at the crossing, the circuits of which are closed by the depression of the treadle members.

Another object of the invention is to so arrange the treadle members that the circuits to the signal means will be alternately closed and opened by a train approaching the crossing so that the signal means will be operated intermittently, thus calling attention to the fact that the train is approaching the crossing.

This invention also consists in certain other features of construction and in the combination and arrangement of the several parts, to be hereinafter fully described, illustrated in the accompanying drawings and specifically pointed out in the appended claim.

In describing the invention in detail, ref erence will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which Figure 1 is a plan View of portion of a track, showing a treadle member arranged thereon.

Figure 2 is a side View, with parts broken away.

Figure 3 is a plan view of the crossin Figure i is a detail View, with parts broken away to show the contacts.

Figure 5 is a section on line 55 of Figure 2.

Figure 6 is a section on line 6-6 of Fig ure 2.

Figure 7 is a diagrammatic plan view, showing the circuits.

In these views, A indicates the track and B the crossing. A plurality of treadle mem-- bers 1 is arranged adjacent one rail of the track so that a train approaching the crossing will have its wheels contact these treadle members and depress the same. Each treadle member is formed of an elongated bar having its ends tapered, as shown at 2, and vertically movable in a casing 3 which is suitably fastened to the track. The treadle member is formed with depending projections 4 which pass through holes 5 formed in the lower part of the casing. Springs 6 are arranged between the bottom of the casing and the lower edge of the corresponding treadle member and act to hold the treadle member in raised position. A contact 7 is arranged on the lower edge of each treadle member at the center thereof and a spring contact 8 is arranged in the casing under the contact 7 so that when the treadle member is depressed, the two contacts will engage each other. Conductors 9 and 10 are connected with the contacts, the conductor 10 being connected with one of the line wires 11 and the conductor 9 being connected with the signal lamps 12, or other signal means which are placed one at each side of the track and one at each side of the crossing, as shown in Figures 3 and 7. These signals are electrically connected with the other line wire 13.

The line wires 11 and 13 are connected with any suitable source of current. The casings 8 are each formed of an upright plate having an inwardly extending flange at its bottom which is seated on the outer part of the base of a 'rail of the track so that the rail forms one wall of the casing, with the treadle member placed in the space between the rail and the upright plate. The projections 4 pass through holes formed in the flange and the base of the rail.

As shown in Figure 7, a number of these treadlle members are used, these members starting at a point adjacent the crossing and ending at a point a considerable distance from the crossing so that when a train approaching the crossing strikes the first treadle member, it will depress the same and thus close the circuit to the signals. The springs will raise the treadle member as soon as the wheels of the train pass therefrom so that the circuit to the signal means will be broken. Then the train strikes the second member and closes the circuits again and this will keep up until the train reaches the crossing. Thus the signal means are intermittently operated and this intermittent operation will be more liable to attract attention than if the signals remained operative all the time during the approach of a train.

It is thought from the foregoing description that the advantages and novel features of the invention will be readily apparent.

the rail forms one wall of the casing, and a flange on the bottom of the plate overlapping a top part of the base of the rail, depending projections on the treadle member passing through holes in the flange and said base, spring means for holding the treadle member in raised position, signal means adjacent the crossing, a circuit for the same and means whereby the circuit is closed by the depression of the treadle member.

In testimony whereof I afiix my signature.

FRANK B. SMITH. 

